There is a need in the media arts to automatically identify particular media programs that are presented. For example, in order to determine copyright royalties that are paid based on the number of times a song is publicly played, e.g., on the radio, it is, of course, preliminarily required to determine the number of times that the song is played. Most often, in the prior art, the number of plays is tabulated based on radio station play logs. However, since these logs are manually entered, there may be errors. Similarly, there is a need to keep track of the actual number of plays of various commercials, whether on radio or television, as well as other programs. For example, many actors receive so-called residual payments based on the number of times a program in which they appeared is played. It also may be desirable to determine and log which programs are played to monitor particular contractual obligations that specify a maximum number of plays for specific programs.
In the prior art, it was possible to identify the content of a media program being presented at any given time on a channel if the content of the media program had additional information identifying the program content embedded therein, or directly associated therewith. Disadvantageously, versions of the media program that do not have available the additional information cannot be identified.
U.S. Pat. No. 4,677,466 issued to Lert, Jr. et al. on Jun. 30, 1987 discloses a system that uses a signature extracted from multimedia content after a stability condition is detected to identify the multimedia content. Such a system does not require additional information to be added to the media program to be identified. Also, Robust Audio Hashing for Content Identification by Haitsma et al., published at Content-Based Multimedia Indexing (CBMI) conference of 2001 in Brescia, Italy, and their believed corresponding United States patent application Publication US 2002/2178410, disclose an automatic content recognition system based on hashing that does not require additional information to be added to the media program to be identified. These systems have not, as of yet, achieved commercial success.